<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    *{
        margin: 0;
        padding: 0;

    }
    .box1 {
        width: 400px;
        height: 400px;
        background-color: orange;
    }
    .box2 {
        width: 150px;
        height: 150px;
        background-color: skyblue;
    }
    .box1:hover {
        background-color: red;
    }
    .box1:hover .box2 {
        background-color: #f6f6f6;
    }
    

    .cover1{
        
        width: 400px;
        height: 400px;
        border: 2px solid royalblue;
    }
    .over1 {
        
        width: 150px;
        height: 150px;
        border: 2px solid red;
        margin: 100px 0 0 80px;
        
    }
</style>
<body>
    <div class="box1">
        <div class="box2"></div>
    </div>

    <div class="cover1">
        <div class="over1"></div>
    </div>
</body>
</html>